SALT TOLERANCE IN CELL-SUSPENSION CULTURES OF THE HALOPHYTE KOSTELETZKYA-VIRGINICA

Tolerance to NaCl was studied in cell suspension cultures of Kosteletzkya virginica (L.) Presl. (Malvaceae), a dicotyledonous halophyte that grows in tidal marshes of the eastern United States. Growth of salinized cultures was significantly inhibited at high (255 mol m-3 NaCl), but not at lower external salinities. Adjustment of cell suspensions to NaCl was rapid, with the duration of the normal growth cycle unaffected by salinity. Maximum biomass was attained when cultures were exposed to NaCl during early log growth. Patterns of inorganic ion accumulation reflected the utilization of both Na+ and K+ as osmotica, with Na+ content substantially increasing when cells were grown at an external salinity sufficient to reduce growth. K+ uptake selectivity was high and Na+/K+ ratios were low in salt-treated cultures even though K+ content was somewhat lower compared to unsalinized cultures. Free proline and microsomal lipid content increased in salt-treated cell cultures.